Samick hammer knuckles HARD!!

[atonal@planet.eon.net]

> Greetings All,
>               This weekend I intended to change a set of knuckles on a 5'8"
> Samick manufactured grand (Wurlitzer) that exibited severe clicking and
> clacking! Re;several fairly recent post.
>   Since I had intended to change the knuckles, I thought this would give me
> an ideal opportunity to experiment.
> 
>   1. Observations:  The leather or composite material was not hard but
> quite   pliable. The core felt was like rock, looked like woven wippen felt
> that had   glue wicked into it. The leather was not firmly around the core
> felt.

I agree, the leather is not the red buckskin variety, but what 
appears to be a pliable, brown doeskin. It doesn't appear to be the 
problem re: action noise. However, the looseness of the leather on 
some knuckles makes me leery of the leather stretching technique: 
getting an instrument in between the knuckle and core felt and 
working around the knuckle curve. This merely loosens the leather and 
provides some cushion for the hammer shank assembly as it returns to 
rest, at the expense of smooth escapement and return.  

>   2. Experiment#1 Laterally needle the felt. Results; very marginal
> improvement,
>   an exercise in futility.

... and broken needles
 
>   3. Experiment#2 Bolster out the leather with 4 thicknesses of fairly
> thick   darning wool. This made a significant improvement in noise
> reduction, but I   did not like the little tuft of wool end, or the slight
> deformation of the      knuckle, but I'll keep this one in my bag of tricks
> as a practical field        repair.

Also, the wool provides a cushion, and fills out the knuckle nicely, 
however the rock-hard inner felt remains untouched. Probably not an 
issue for several years, until the softer wool felt begins to 
compress. 

>   4. Experiment#4 Scotch and water teatment????  Not quite! 50% alcohol/water,
>   upend action, leaning against bench, use an eye dropper and wet the core
> felt,
>   turn the action up side down and repeat on the opposite side of felt,
> left   over night to dry with the hammers up and off wips, big improvement,
> not a lot   of hassel. 

Oh, I don't know, I find 50:50 alcohol/water mixed and applied 
liberally to the service technician results in reduced action noise, 
and increased lubrication. 8-) 
	I would add that keeping a hot hammer iron handy and just touch the 
wet core felt to gently steam the inner felt once you have added the 
mixture to the knuckle.
 
>   5. Experiment#5 STEAM  Not again?    Kettle with whistle removed has a
> nice     1/8"   dia hole, we use it for key bushing removal. Good jet of
> steam that is   small.
>   Removed hammers one at a time and steamed core felt on both sides. Wow
> did   they puff up, leather nice and firm against core, geometry looks
> good, hammers   left off wips to dry. 
> 
>   48Hrs later. Hair drier used on the knuckles at the 24Hr interval, the
> steamed  knuckle felt, was the quietest and is acceptable. How ever it is
> the most time consuming by far because of hammer removal. A needle test was
> performed to compare with Experiment#1 a clear improvement on core density.
> Time will tell if the treatment is long lasting, however I have used steam
> in several other applications that I'm quite optomistic of the out come. If
> it last it will be much quicker than replacing knuckles.

Lots 'o work for this one, I would use this as a last resort if a) 
replacement is not an option or b) someone (private, factory or 
dealer) is footing the bill, and is aware that this is the best you 
can do with the existing knuckles.
 
>   Tomorrow I'm going to invent a steam diven tuning hammer and market
> through K-Tel.

Don't forget the steam-powered backpost bender, handy for those 
tricky timber alignment jobs. 

>   Thanks Rob for sharing your inputs.

Shucks, t'wernt nothin'

>  Yours the closet steamer.
>  
> Roger Jolly
> University of Saskatchewan
> Dept. of Music.
> 
Rob Kiddell, 
Registered Piano Technician, PTG
atonal@planet.eon.net